Ulyana V. Khomutova

A composite material based on polyvinyl alcohol (PVA) and hydroxyapatite modified with magnesium (0.3; 0.5; 1.0 mol) was developed using the in situ mineralization method. A thorough analysis confirmed the formation of a two-phase system, with a uniform distribution of HA particles within the PVA matrix. In addition, the analysis confirmed the successful incorporation of magnesium into the crystal lattice without the formation of secondary phases. The material exhibited a developed macroporous structure, with porosities ranging from 50 to 200 μm. In order to ensure that the rheological properties of the composition were suitable for 3D printing, 4 wt.% gelatin was added, resulting in stable scaffolds. In vitro studies demonstrated high biocompatibility of the materials and a synergistic effect of the components: PVA has been demonstrated to neutralise the cytotoxic effects of HA, while magnesium has been shown to statistically significantly increase the viability of macrophages. The combination of a polymer matrix with an inorganic phase results in a material that exhibits both elasticity and bioactivity. The structural and functional characteristics of these systems render them promising materials for tissue engineering, particularly for bone regeneration and the creation of biocompatible 3D scaffolds.

The effect of surface modification by an arc discharge plasma in a nitrogen flow with treatment durations of 5 and 10 min on the physicochemical properties and biocompatibility of the surface of composites based on polylactic acid and hydroxyapatite (PLA/HA) with different mass ratios (80/20, 70/30, 60/40) has been investigated. The aim of this work was to show the correlation between the changes of the physicochemical characteristics (chemical compound, morphology, wettability) of the surface layer of the PLA/HA composites and the cell viability (macrophages) in the presence of the plasma-modified materials. The dependence of alterations of the functional properties (wettability, biocompatibility) on the change in the chemical composition under the plasma exposure has been established. The chemical composition was studied using X-ray photoelectron spectroscopy (XPS), the surface morphology was researched with scanning electron microscopy (SEM), and the wettability of the composite’s surface was analyzed by measuring the contact angle and surface energy calculation. In addition, the viability of macrophages was investigated when the macrophages from three donors interacted with a modified PLA/HA surface. It was found that the formation of the new functional groups, –C-N and N-C=O/C=O, improves the wettability of the surface of the composites and promotes the viability of macrophages in the presence of the composite materials. The fundamental principles for obtaining promising materials with the required properties for eliminating bone defects have been created.

The effect of low-temperature arc discharge plasma treatment in a nitrogen atmosphere on the modification of the physicochemical properties of PLA-based scaffolds was studied. In addition, the cellular-mediated immune response when macrophages of three donors interact with the modified surfaces of PLA-based scaffolds was investigated. PLA surface carbonization, accompanied by a carbon atomic concentration increase, was revealed to occur because of plasma treatment. Nitrogen plasma significantly influenced the PLA wettability characteristics, namely, the hydrophilicity and lipophilicity were improved, as well as the surface energy being raised. The viability of cells in the presence of the plasma-modified PLA scaffolds was evaluated to be higher than that of the initial cells.